Structural and magnetic phase diagram of CeFeAsO(1- x)F(x) and its relation to high-temperature superconductivity.
Recently, high-transition-temperature (high-Tc) superconductivity was discovered in the iron pnictide RFeAsO(1-x)F(x) (R, rare-earth metal) family of materials. We use neutron scattering to study the structural and magnetic phase transitions in CeFeAsO(1-x)F(x) as the system is tuned from a semimetal to a high-Tc superconductor through fluorine (F) doping, x. In the undoped state, CeFeAsO develops a structural lattice distortion followed by a collinear antiferromagnetic order with decreasing temperature. With increasing fluorine doping, the structural phase transition decreases gradually and vanishes within the superconductivity dome near x=0.10, whereas the antiferromagnetic order is suppressed before the appearance of superconductivity for x>0.06, resulting in an electronic phase diagram remarkably similar to that of the high-Tc copper oxides. Comparison of the structural evolution of CeFeAsO(1-x)F(x) with other Fe-based superconductors suggests that the structural perfection of the Fe-As tetrahedron is important for the high-Tc superconductivity in these Fe pnictides.
Zhao
Jun
J
Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200, USA.
Huang
Q
Q
de la Cruz
Clarina
C
Li
Shiliang
S
Lynn
J W
JW
Chen
Y
Y
Green
M A
MA
Chen
G F
GF
Li
G
G
Li
Z
Z
Luo
J L
JL
Wang
N L
NL
Dai
Pengcheng
P